At a cash register in retail stores such as supermarkets, department stores, and convenience stores, a POS terminal reads a product identification label such as a bar code attached on a package of a product, and the product is checked out. However, there are products such as vegetables and fruits to which a product identification label is difficult to be attached in a readable manner, and products such as a bag of rice and a box of beer of which product identification label is difficult to be read at the cash register. These products cannot be checked out using the product identification label in the manner as described above, and hence, a POS terminal displays a checkout panel screen in which product buttons corresponding to these products are arranged. A register operator operates this checkout panel screen through a touch panel, thereby checking out a product corresponding to the product button operated. Hereinafter, a product, which is checked out through the checkout panel screen without using the product identification label, is also referred to as an unlabeled product.
Patent Document 1 described below proposes a technique that allows a user to freely and easily change the layout of screen parts corresponding to respective products on an order input screen. Patent Document 2 described below proposes a method of, if a product that has not been registered in a product master is found, scanning a bar code on the product while capturing an image of the product in order to make it easy to register the product in the product master at some time in the future using the image of the product captured. Patent Document 3 described below proposes a method of, if product register information corresponding to a product code is not registered in a PLU file, setting a product image captured by a scanner and an inputted unit price for the product code, and additionally registering it to the PLU file.